W

Select section: Substituting the above service load moments into Equation 4.78, we have

70 x 12 20 x 12 Sx --1--< 0 .60(50) or 840 + 240— < 30Sx

Sx Sy Sy

For W-sections with depth below 14 in. the value of Sx/Sy normally falls in the range 3 to 8, and for W-sections with depth above 14 in. the value of Sx/Sy normally falls in the range 5 to 12. Assuming SxISy — 10, we have from the above equation, Sx > 108 in.3 Using the ASD Selection Table in the AISC-i/Toninl lot nc tnr o \K7~> A x ££ co^ti'rjn (Sx — 114 in 3, Sy -